Slush pump piston



Nov. 1, 1966 A. D. PARKER 3,282,172

SLUSH PUMP PI STON Filed Nov. 9, 1964 ALVA D. PARK INVENT United States Patent 3,232,172 SLUSH PUMP PISTON Alva 1). Parker, 905 Frazier Drive,

Oklahoma City, Okla. Filed Nov. 9, 1964, Ser. No. 409,902 1 Claim. (Cl. 92-128) The present invention relates to pistons and more particularly to a double acting piston construction for use in a slush pump, or the like, wherein abrasive materials in suspension, such as in drilling mud, are pumped under pressure.

As a result of the high pressures and the abrasive nature of drilling mud conventional slush pump piston rings or packing is soon worn out and must be replaced. Replacing the packing on slush pump pistons generally requires removing or pulling the piston rod from the pump which is a costly and time consuming operation. Pulling the piston rod to remove the piston from the slush pump for replacing piston packing rings further requires the removal and replacement of the packing in the stufling box through which the rod extends requiring a further expen- I diture of time and money.

It is, therefore, the principal object of the instant invention to provide an improved double acting piston construction for a slush pump, or the like, which can be quickly and easily placed on and removed from the tapered end portion of a piston rod from the head end of the pump without pulling the rod from the pump.

Another object of the invention is to provide a piston construction of the general character referred to which employs few parts in addition to a conventional piston which parts are integrally formed on one end of the piston and are highly effective and dependable for piston removal.

Another object is to provide a piston construction wherein the piston removal features added to the piston body do not contact and wear the cylinder wall of the pump.

A further object is to provide a slush pump piston having means formed thereon for receiving and engaging a piston and rod separating tool which maintains the piston coaxial with respect to the pump cylinder so that the cylinder wall of the piston will not be damaged during removal of the latter from the piston rod.

The present invention accomplishes these and other objects by forming a coaxial extension on the piston body, at one of its ends, which is adapted to be engaged by a piston removal tool.

Other objects will be apparent from the following description when taken in conjunction with the accompanying single sheet of drawings, wherein:

FIGURE 1 is an elevational view, partly in section, of the piston connected with a piston rod;

FIGURES 2 and 3 are vertical cross-sectional views taken substantially along the lines 22 and 3-3, respectively, of FIG. 1; and

FIGURE 4 is a vertical cross-sectional view of the piston and piston removing tool in piston removing position.

Like characters of reference designate like parts in those figures of the drawings in which they occur.

In the drawings:

The reference numeral indicates a slush pump piston, as a whole, connected with a piston rod 12. The piston 10 includes a generally cylindrical body portion 14 having an axial tapered bore 16 adapted to tightly fit a cooperating conical or tapered end portion 18 formed on the piston rod. Thus the tapered bore 16 defines an opening at one end 20 of the piston and a smaller bore at the other end of the piston body. A nut 24, threadedly engaged with the free end of the piston rod, normally holds the piston 10 on the rod 12. An annular flange 26 surrounds the piston body 14 near its mid-section. A pair of piston rubbers or packing rings 28 surround the piston body 14 in contact with the flange 26. A pair of end plates 30 surround the piston body 14 in juxtaposition with an end surface of the respective packing ring 28. A pair of snap rings 32 and 33 surround the piston body within suitable grooves 34 to maintain the end plates in position against the packing rings 28.

The above description is conventional with pistons presently used in slush pumps and is set forth to define the normal construction of pistons presently in use.

In carrying out the invention, the small diameter end of the body has an extended portion, indicated generally by the numeral 40, coaxially formed thereon. The portion 40 is diametrically equal with respect to the piston body 14 and is circumferentially grooved, as at 42, between its free end 41 and the sealing ring 33 to define a flange 44. The portion 40 is further provided with diametrically opposed grooves or slots 46 extending rearwardly of the forward end 41 of the portion 40 and intersecting the flange 44 and the groove 42 thus dividing the flange 44 into a pair of opposite flange portions. A partition-like projection is extended from one end edge of each flange 44 across the groove 42 to divide the groove 42 and form a stop 48. Thus the slots 46 and respective intersected portion of the groove 42 form J-slots opening at their hook portion to the end edge surface 41 of the piston projection 40 while the stops 48 form a blind end for the leg portion of the respective J-slot.

As shown in FIG. 1, the nut 24 bears against the forward end 41 of the extension or portion 40 to hold the piston in place on the rod 12.

The piston 10 is removed from the rod 12., after removing the nut 24, by a piston removing tool, indicated generally by the numeral 50. The tool 50 comprises a sleeve 52 having an enlarged bore 54 in one end portion. The sleeve 52 is provided at its open end with a pair of oppositely disposed inwardly extending lugs or flanges 56 which are slidably received by the slots 46 and rotated into the grooves 42 wherein the rotating movement is arrested by the stops 46. The other end of the sleeve 52 threadedly receives a bushing 58. An elongated bolt or mandrel 6% is threadedly inserted into the bushing 58 so that its inwardly disposed end portion 62 engages the adjacent free end of the piston rod 12. Thus tightening the bolt 60 against the rod 12 exerts a pull On the flanges 44 of the piston extension 40 to remove the piston from contact with the piston rod.

Obviously the invention is susceptible to some change or alteration without defeating its practicability, and I therefore do not wish to be confined to the preferred embodiment shown in the drawings and described herein, further than I am limited by the scope of the appended claims.

I claim:

A piston to be used in conjunction with a piston rod having a conical portion near one end, comprising: a cylindrical piston body having a conical axial opening adapted to fit tightly on the conical portion of said piston rod, said piston having an annular radial flange near its mid-section; a pair of piston packing rings disposed over the ends of the piston body; and packing ring retaining means engaging the piston body to hold the packing against said flange, the end of said body having the smaller diameter opening including a portion extending coaxially beyond the packing retaining means at that end, said portion corresponding in diameter to said body, said portion having a pair of J-slots formed in its outer surface to engage a pulling tool, the hook portion of each ]-slot being oppositely disposed diametrically of said portion, the leg portions of the J-slots extending partially around said portion in circumferential alignment forming a blind end for each J-slot leg portion, each I-slot leg portion having a width substantially equal to the spacing between the respective J-slot leg portion and the end surface of said body having the smaller diameter end, the width of each I-slot leg portion being substantially greater than its spacing from the packing retaining means at that end of said body, said portion being integrally connected through said body to said flange whereby when a pull is exerted on said portion it pulls both of said packing rings and said flange to remove them simultaneously from the 1 rod with the remainder of the body.

References Cited by the Examiner UNITED STATES PATENTS 1,977,075 10/1934 Magnuson 92-128 X 2,566,994 9/1951 Phipps 92128 X 2,731,315 1/1956 Church 92128 X MARTIN P. SCHWADRON, Primary Examiner.

EDGAR W. GEOGHEGAN, Examiner.

I. C. COHEN, Assistant Examiner. 

